A hash function is:
a. A one-way function that uses a cipher to produce a piece of data that helps to encrypt other data
b. A two-way function that, used in conjunction with a key, takes cleartext and encrypts it into ciphertext
c. A one-way function that creates a random number as a digital signature
d. A one-way function that mathematically manipulates the input data to create an output value
Answer: D